1. Field of the Invention
Aspects of the present invention relate to an apparatus and method for managing power supply in a Power over Ethernet (PoE) system. More particularly, aspects of the present invention relate to an apparatus and method for reducing power consumption in a PoE system.
2. Description of the Related Art
A PoE system uses a PoE control unit to supply power to devices connected to an Ethernet interface. For example, a conventional PoE system generally supplies power according to a process illustrated in FIG. 1.
FIG. 1 is a flowchart illustrating a conventional process for supplying power in the PoE system. Referring to FIG. 1, a device connects to an Ethernet interface in step 101. In step 103, the PoE system determines whether power supply is available to the device. If power supply is available to the device, the PoE system supplies power to the device in step 109. On the other hand, if power supply is not available to the device, the PoE system determines the PoE priority of the device in step 105.
In step 107, the PoE system determines whether another device has a lower PoE priority. If there is a device that has a lower PoE priority, then in step 113 the PoE system withdraws the power supply to the device with the lower PoE priority. Thereafter, the PoE system returns to step 103 to again determine whether power supply is available to the device.
On the other hand, if no other device has a lower PoE priority, then in step 111 the PoE system restricts the power supply to the device. Thereafter, the PoE system ends the power supply process.
As described above, the conventional PoE system determines whether to supply power and maintain power supply based on the total power resources and the PoE priority information of the interface. Accordingly, the conventional PoE system may supply power even to an unauthenticated device, thus causing unnecessary power consumption.
The PoE control unit periodically senses devices to detect whether there is a device connected to the interface. The PoE control unit also continues to measure the power consumption of a device connected to the interface, and calculates the total power consumption of the interface to manage the total power resources. If the PoE system supplies power even to an unauthenticated device, the PoE control unit monitors the power consumption of even the unauthenticated device, thus unnecessarily increasing the load of the PoE control unit.